Quantitative determination of naphthalene in illuminating gas



Jan. 23, 1923.

1 FULWEILER QuANTlTAT VE DETERMI NATION 0F NAPHTx-MLENE IN I LLUMINATING GAS 2 SHEETS-SHEET 2 IFx LED JAN. 12. 1922 .v

Patented dan. 23, 11923..

P A T if WALTER H. FULWEILER, OF WALLINGFORD, PENNSYLVANIA, ASSIGNOR TO THE U. G. I. CONTRACTING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A COR- PORATION OF DELAWARE.

QUANTITATIVE DETERMINATION OF NAPHTHALENE IN4 ILLUMINATING GAS.

Application led January 12, 1922. Serial No. 528,861.

To all wiz ont-t may concern Be it known that I, laurita H. FUL- wEiLEn, a citizen of the United States, residing atllvallingford, in the county of Delaware and State of Pennsylvania, have inl vented a new and useful Improvement in the Quantitative Determination of 'Naphthalene in Illuminating (ias. of which the following is a specification.

The principal .objects of the present invention are to provide for the rapid and accurate quantitative determinatiton of naphthalene in illuminating gas even by un-y skilled persons, to provide a simple, expeditious and reliable method for that purpose, .and to provide portable, compact, and comparatively inexpensive apparatus by means of which the method can be practiced.

In the practice of the invention the naph` thalene content of the gas is converted into na-pthalene picrate by passing a known quantity of gas through a standard solution of picric acid thereby increasing the electric resistance of the solution, and the value of the electric resistances of the treated and of the standard solutions are compared thereby estimating quantitatively the naphthalene content of the gas.

The invention comprises the improvements to be presently described and finally clamped and the description will be made in connection with the accompanying drawings forming part hereof and in which- Figure 1 is a top or plan View of conductivity bridge apparatus with the cover removed and parts omitted and which embodies features of the invention.

Fig. 2 is an elevational view of the right hand end part of the apparatus shown at the bottom of Figure 1 vwith parts omitted.

F ig. 3 is a transverse sectional View taken through the lower portion of Figure 1.

Fig. 4 is a view diagrammatically showing a train of gas washing bottles and also indicating a meter.

Fig. 5 is a diagrammatic view illustrating the circuit connections of the apparatus shown in Figure 1.

Fig. 6 is a chart for showing the naphthaiene concentration from readings taken by the apparatus of Figure 1, and

Fig. 7 is a 'View of a chart for another use in connection with readings taken from the apparatus shown 1n Figure 1.

In the drawings, more particularly Fig. 5,

there is shown an electric balance having two of its arms, 1 and 2, provided with conductivity cells 3 and 4 land having its bridge 5 provided with a balance indicator indicated generally at (i, and with a balance adjuster generally indicated at 7. S and 9 are the leads of an alternating current circuit provided with a switch 1() for making and breaking it. 11 is a step-down transformer shown as an auto transformer interposed in the alternating current circuit and across which the electric balance is connected as by conductors 12 and 13. 14 is an inductive resista-nce 1n series with the step-down transformer 11 and with the field winding 15 and serving to 70 limit the current passing through the apparatus. The field \vinding,15 appertains to the balance indicator 6 which is shown as an alternating current galvanometer having fixed poles 16 and a fixed core 17 and a mov- 75 able coil 18 which carries the pointer 19, Fig. 1. The balance adjuster 7 is lshown as a key 2O co-operating with a scale,21,"`l4`ig. 1, and adapted to be connected with points of different potential in the coil 22, and the coil 22, and the coil 23 are of equal resistance when the adjuster is in zero position. The arms 24 and 25 are of equal resistance. The conductivity cells have the same constants and are alike so that a description of electrode 26, and by pushing the rod 28 in 90 and pulling it out the constant of the cell can be adjusted. 29 is a thermometer for showing the temperature of the contents of the cell. The funned 30 and -tube'31 con* stitute an inlet for the cell, and the tube 32 95 constitutes an overflow for the cell, thus the liquid is introduced from the bottom of the cell in excess and air bubbles are avoided. 33 is a pinch connection by which the cell lcan be emptied. 34 is a known resista-nce 100 that may be connected by binding posts 35 across the conductivity cell 4 for a purpose to be presently described. The described parts are assembled in a cabinet 36 in such 1ro ofivashing bottlesshown in Fign14"V and which a way -that some of them are expos'd as shown in Figures 1 and l3 when thelid of the cabinet is open or removed, and others ofthe parts are concealed within the cabinet. 37, is la socket for the reception of' a line plug.''j"l`he.bracket 38 may be; turned about I thelpivot 39 and it serves'to support the furuiel's.`v l.The apertures 40- serve for the rece tionv of. the connections 31 vand 32. The was ing ,bottles 41,42 and 43 of thetrain 'includes a Smeterindicated' Vat 4 5, are itha-standard solution'of picric' acid.- ashing' bottles 46' and 47 containv rejigentsand 'when present they serve to moveffcertaini 'ingredientsother than naphthalene from the 'gasf- In "makinga test gasls`v vpassed through the'. train'i of'washingbottles at an appro- 2.0 ceeding .8 `cubic'feet lper .hour until a rdispriate rate-,Ufer example, a 'irate not extinct precipitate appears in bottle41. The flowof' gasv is `then stopped and the appro-v priate meter readings Hmade.. The train. isI then disconnected and the contents of bot- `tles' .46," and 47 discarded; Bottles` 41, V42

and -43 are thenl brought` to approximately w25@ C., for example, from' 27 to 23 C., and are `allowed to remain'lat that temperature orously shaken.: Bottle 41 contains the'infor a few moments andethen they are vig Y soluble naphthalenefpicrate and the bottle 42'is a catch bottlelforjinsoluble picrate.

" The bottle 43 vcontains' standard picric acid the solution as it may have"been modified by passageofv gas through it. The eleca tric 'resistancesfof the standard.v solution and of the contents'of the bottle 41, and

- perhaps the bottle 4 2, are'notthesame, vthe ductivityi vFilter pape funnels-30 andk the contents .of 'bottle 41 is' standard solution of greater` confiltered into, for example, the righth-and conductivity cel1 4 and the contents of v,bottlex43 is vlteredl into the lefthand conductivity cell' 3., In both cases fthe additions L l'each other. `v'I 'Jhe absolute ltemperature 'is not so vimportant las the Vrelative temperature.

The circuit isthen completed, for example,

by'pressing thev push button v`10, and the balance ad]uster Iris turned A'until the 'balancel indicator 6` stands atzero. The push button can then'be releasedand the read'- mg'of the dial 2 1 andV ofthe thermometers 29 observed. 1 They resultofthisis-.fthat the value of the electric 4resistances of thegstand# ard andl of the other solution; are compared and the relative dierence noted on the dial are puty into the Vof a neutral solutionof cadmiumchloride.

I do not cla'r'n herein the vapparatus' as 21. The scale reading at 21 is noted along the horizontal line of the chart shown 'in Fig.` 6 and is temperature lines on the chart as indicated, for example, at a, and atV the intersection of the line a with lthe observed temperature line b, and at the left as indicated bythe line c, will be found as at e the'grains of naphthalene pr hundred cubic feet-of gas when one cu ic foothas been .used asa carried up to the calibrated sample. In most cases it is unnecessary toy -f vmeasure the resistance of the contents of However, some naphthalene may have reached bottle 42 and tin such case a small amount of the solutionin bottle` 'L12-'is filtered in and used .to wash out. the

bottle 42,

cell 4, andthe cell is then lilled With the solution from bottle 42 and the difference in resistance determined as before. In case both bottles 41 and 42 are read on esi the dial 21 the curve is'entered with the sum of the dial readings.

The standard picric acid solution may well be approximately av saturated solution at 25 C. Such a solution is'madeup and poured into the cell 3 ,which can be well washed out with it. The fixed resistancel 34 is then connected to the .binding post Z55- and a reading made .onthe dial 21.` 4The I calibrated curve for the stand-ard ypicric acid solution shown in Fig. '7. is then`.-referred to by applying, the temperaturel reading at the left as indicated ata, and if thev read# ing of y at ythebottom ofthe chart does not" agree with the reading onthe sca1e' ,21, the proportions are changed `,until these readings agree. v

v In the description '4 and claims reference is made to naphthalene, but the invention is applicableto the determination of ammonla and h drogen 'sulphide by using appropriate so utions, for example, for amand for hydrogen sulphide use can be madethe same forms the subject matter of my .monia'use can be .made of sulphuric acid,

application for LettersPatent, SerialNo'.

571,717, filed June 29', 1922.

It will be obvious to .those'skilled in the vartto Which the inventionrelates that modi f fcations 4may bemadelnot only in .procedure but "also in construction `and arrangement Without departing from the spirit. of the `Invention which is not limited as to those matters or otherwise than las the prionart andthe'appendedclams may require:

"I-,claimz' 1.,'I`hemethod for the quantitative de'-r i termination of naphthalene in illuminating'.

gas `which consists in converting jthe naphv thalene content of theV gas" into naphthalene picrate bypassing a known quantityfof'they gas "througha' standard .solution of picric acid .thereby increasing theelectric resistisc icc l.

ance of the solution, and comparing the value'of the electric resistances of the treated and of the standard solutions thereby estimating quantitatively the naphthalene con tent of the gas.

Q. The method for the quantitative determination of naphthalene in illuminating gas which consists in passing the gas through two samples of standard picric acid solution to convert the naphthalene into picrate in one sample and to modify the electrical resistance of the other sample in respect to the'action of constituents of the gas other than naphthalene, and comparing the value of the electric resistances of the two samples thereby estimating quantitatively the naphthalene content of the gas.

3. In the method for the quantitative determination of naphth-alene in illuminating gas the ste of preparingthe standard solution of picric acid which consists in preparing a trial solution of picric'facid and balancing the electric resistance of the trial solution with an electrical resistance of fixed value, and adjusting the roportions of the ingredients of the trial so ution until its electrical resistance and the electrical resistance of fixed value are equal.

WALTER H. FULWEILER. 

